yes there is another way, that is:
* register a preview callback to camera.
* convert byte array provided to callback from YUV to some format that jPCT can handle
* make or update a texture out of that
* blit that texture to frame buffer before any other 3d content
despite the overhead of yuv -> jpeg -> texture -> upload cycle, this runs 40 fps (which is vSynch limit I Suppose) on Samsung S3. I'm just trying to figure an easier way.